A typical prior connector of adjacent cell components of an electric storage battery has been disclosed in the U.S. Pat. Nos. 3,313,658 and 3,897,269 issued on Apr. 11, 1967 and July 29, 1975, respectively. The connector of these patents comprises connector straps positioned to face each other through an opening in a corresponding partition wall of a battery case in compartments of which the cell components are contained, respectively. One of the connector straps is provided on positive plate lugs for one of the adjacent cell components to connect the positive plate lugs while the other connector strap is provided on negative plate lugs for the other adjacent cell component to connect the negative plate lugs. Providing the connector straps on the plate lugs causes the process of producing the connector to be troublesome because the straps have to be provided by casting. The faced connector lugs are projection-welded through the opening in the corresponding partition wall. To do this, the connector lugs are essentially in contact with each other by any suitable means. It has been disclosed in the prior art that, to this end, one of the connector lugs has a nose provided thereon while the other connector lugs has a depression provided therein to be forced past the nose of the one connector lug. Alternatively, both of the faced connector lugs have projections provided thereon, respectively, to be in contact with each other through the opening in the partition wall. Otherwise, an intermediate insert member positioned in the opening in the partition wall is placed between recesses in the faced connector lugs. However, any of these makes the cell components to be placed in the compartments of the battery case with difficulty because the nose, the projections or the intermediate insert member interfere with the corresponding partition wall or the connector lugs. Thus, it will be noted that the prior electric storage battery could not be produced with effectiveness. It will be also noted that there are required at least two welded portions between the plate lugs and the connector straps and between the faced connector lugs, which causes the electrical resistance between the adjacent cell components to be increased and therefore the electrical characteristic to be deteriorated.